Syringes or drugs used according to study group. Group A: 5 mg Remifentanyl in 50 cc (100 ug/ml). Bolus of 2 ug/kg IBW (0,2 ml / 10 kg IBW) followed by 10 - 50 ug/kg IBW/h (1 - 5 ml / 10 kg IBW / h) Group B: Sevoflurane inhalation 1 MAC in O2/air Group C: 200 mg rocuronium in 20 cc (10 mg/ml). Bolus of 1 ml / 10 kg IBW followed by 1 ml / 10 kg IBW/h